Selective trip circuit breaker with instantaneous trip during closing



Aug. 26, 1958 w. M. SCOTT, JR

SELECTIVE TRIP CIRCUIT BREAKER WIT INSTANTANEOUS TRIP DURING CLOSING 5 Sheets-Sheet 1 Filed July 22, 1954 534 INVENTOR. td/zunm/ z'carn/z.

Aug. 26, 1958 w. M. SCOTT, JR 2,349,559

SELECTIVE TRIP CIRCUIT BREAKER WITH INSTANTANEOUS TRIP DURING CLOSING Filed July 22, 1954 5 Sheets-Sheet 2 INVENTOR. 532 [Z/xu MM A7. carr/e.

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SELECTIVE TRIP CIRCUIT BREAKER WITH INSTANTANEOUS TRIP DURING CLOSING 5 Sheets-Sheet 3 Filed July 22, 1954 Aug. 26, 1958 w, sco -r, JR 2,849,569

SELECTIVE TRIP CIRCUIT BREAKER WITH INSTANTANEOUS TRIP DURING CLOSING Filed July 22, 1954 5 Sheets-Sheet 4 INVENTOR. W/lZ/l M/Z SZVrrs/i.

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SELECTIVE TRIP CIRCUIT BREAKER WITH INSTANTANEOUS TRIP DURING CLOSING Filed July 22, 1954 5 Sheets-Sheet 5 I 444 hl o 0 73 I I I o IN V EN TOR.

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United States Patent Ofilice 2,849,569. Patented Aug. 26, 1958 SELECTIVE TRIP QRCUIT BREAKER WITH INSTANTANEQUS 'llRIP DlURlNG= CLOSING- William M. Scott, Jr Bryn Mawr, Pa., assignor-to I.-T-E

Circuit Breaker Company, Philadelphia, Pa., a corporation of Pennsylvania Application July 22, 1954, SerialNo; 445,123

6 Glaims. (Cl. 200108)- My invention-relates to selective trip circuit breakers and ismore particularly directed to a novel arrangement to permit instantaneous trip-free operationof the interrupter when it is closed on a fault. My inventionv is related to novel means to render an instantaneous trip armature operative to enable a time delay circuit breaker.- used in a selective trip system to instantaneously trip open only when it is manually or automatically closing on afault and is an improvement of the arrangementshownin Patent No. 2,536,775 assigned to the assignee of the instant application.

Selective trip systems such as described in Patent No; 2,648,803, assigned to the-assigneeof the instantapplication,.Patent No. 2,486,602, assigned to the assigneeof the instantapplication, are provided with circuittbreakers of the type shown in Patent No. 2,439,165, assigned to the assignee of the instant application, have time delay characteristics for all current values up to the interrupting capacity of the circuit'breaken. Thus, except. for severe short circuit currents, the circuit'breake-r always opens with either long or short time delay characteristics.

When the circuit breaker is latched in the-closedposition the short and long time delay tripping will not harm the interrupter or the: system during the period of the time delay. However, if a fault exists on the line at the time whenan attempt is made to automatically or manually close the circuit breaker, the circuit breaker may be severe ly damaged;

That is, the magnetic forces set up in the loop consist ing of the movable contactwill tend to force the contacts to partially open-position and since this force may be larger than the force tending to close the breaker, the mechanisms will not be permitted to latch closed.

Thus, if the. circuit breaker is provided withtimed'elay characteristics, the trip-free latch is-not disengaged during closing and hence, the circuit breaker is not trip-free.

That is, if the closing force is not sufficient to close and latch the contacts against'the fault current, then .the opening of the breaker will not be trip free until a lapse. of relatively longtime.

This'may result in either injury to the person attempting tomanually close the breaker or in a pumping operation of the'breaker if it is being automatically closed.

It is also noted that if the contacts do not latch closed when the circuit breaker is closed. ona faultcurrennthe arcingcontacts may remain in partial engagement. and chatter; thus, causing excessive arcing damage:: to the contact components of the circuitbreaken. Thattis, since the arcingcontactsmay remain in engagedposition until the time delay for the overcurrent armature has elapsed, the. arcing contacts will be damaged since they are exposed to excessive arcing conditions and are not designed to carry current for any appreciable length of time with the existing. poor Contact engagement.

This undesirable condition cannot be overcome by merely providing more closing force' to overcome the magnetic opening forces. The reason for this'is that the same closing forces are applied whether. or not a fault exists on the line.

If sufficient closing forces are provided to close and latch the circuit breaker against the fault, then a closing operation with this same force, in the absence of opposie tion forces established by a fault, would cause. undue mechanical strain on the breaker.

It is further noted even if the selective trip circuit breaker could be latched closedon .afault line, it would not be desirable to have-time delaytripping; Thatis, it is not necessary to have a circuit breaker. which. has been opened as a result of a fault current operate with time delay characteristics if it is closing. on the same fault since the fault on the line will either exist. close to thistcircuit breaker. or cause a fault currentto flow with a magnitude which only the interrupting capacity of the opened circuit breaken can handle.

Hence, it is doubly desirable to providetn'pped circuit breakers with instantaneous trip characteristics during. the closing operation so that it will. trip open without. time delay in case it is reclosed on the same fault which caused it to trip open originally.

In order to overcome the dangers associated with closing acircuit breaker against fault current under delayed conditions, I'have provided an instantaneous armaturein addition to the longand short time delay trip armature. The" instantaneous triparmatureis effective only during the closing operation of the circuit 'breaker to trip'same without time delay.

However, after the cooperating contacts are. latched closed, the instantaneous armature-is blocked and hence, the circuit breaker has either long or short timetrip characteristics on the occurrence of a faultcurre'nt when the contacts are latched closed. .That is, .thecircuit breaker will have high speed trip characteristics duringthe closing period and time delay characteristics after the'circuit breaker is latched closed.

With this arrangement-if an attempt is made to close the interrupteron a fault current, .thetrip latch will-be released as immediately after a fault current commences to flow even though the. prop latch isnot moved tolatch position. Thus, trip-free operation will occur-as a result of the instantaneous tripping,

I Hence, .with this arrangement, there will be no sustained forces in opposition to the. manual closing meansor to the automatic closing means. causing damage tothearcing contacts as aresult of. an attempted closing on a faulted line.v

It will be noted that there: are several otherinovel methods to achieve the above noted desired results. For example, co-pending application Serial No. 445,094,-filed July 22, 1954, assigned to the assignee of the instant application, provided an arrangementtwhereby the timer arm of the escapementtime delay mechanism is rotated out of the path of its armaturewduring the opening of the circuit breaker and is not returned to its operative position until the circuithreaker is latched closed? Hence, the .circuit breaker willv have instantaneous trip if. the circuitbreaker is closed on. a faultline, but will-have time delay characteristicsafter the circuit breaker-is latched closed. Copending application Serial. No. 445,122, filed July 22,. 1954,.assigned to the assignee of thez'instantiapplication, provides a latch for. the pivot of thetimer housing which is unlatched during the. openingoperation .so that the circuit breaker will trip-free without timev delayif closed on afaultline, Copendingapplication.Serial No. 445,124, filed July 22,..1954, assigned to the.as= signee of the. instant application,:provides an l arrangement wherein. the entire escapement timer' housing is rotated duringtthe openingoperationto render the time delay means ineffectivewhen:thecircuitbreaker is closed on a fault.

Accordingly, a primary object of my invention is to provide a novel arrangement for selective trip circuit breakers wherein high speed or instantaneous tripping occurs for any magnitude of overcurrent only during the closing operation of the circuit breaker due to the unblocking of an instantaneous armature during the opening operation and thereafter when the circuit breaker main contacts are latched engaged has time delay characteristics, at which time the instantaneous armature is blocked.

Another object of my invention is to provide a novel arrangement in which the instantaneous tripping mechanism is rendered operative during the opening operation of the circuit breaker by removing a blocking means for an instantaneous armature and is rendered inoperative after the contacts are latched closed by placing the blocking means in the path of the instantaneous armature.

A still further object of my invention is to provide novel means to remove a blocking means from an instantaneous trip armature when the circuit breaker is being opened and to maintain said blocking removed from said instantaneous armature until the contacts are fully latched closed.

These and other objects of my invention will be apparent from the following description when taken in connection with the drawings in which:

Figure 1 is an exploded perspective view of an operating mechanism of a circuit breaker and shows the cooperating contacts in a disengaged fully open position. This figure illustrates my novel arrangement wherein an instantaneous trip armature is rendered operative when the circuit breaker is moved to open position by unblocking same and remains unblocked until after the contacts have latched closed.

I Figure 2 is a side view of the circuit breaker of Figure 1 and illustrates the position of the various components when the cooperating contacts are in a fully closed posi- 'tion. This figure also illustrates the manner in which the instantaneous armature is blocked after the contacts have latched closed so that subsequent automatic tripping of the circuit breaker will occur with time delay by movement of either the long or short time delay armature.

Figure 3 is a schematic view of the circuit breaker of Figures 1 and 2 and illustrates the position of the various components when the circuit breaker is in the fully closed position of Figure 2. This figure illustrates the latched position of the trip latch and prop latch.

Figure 4 is a schematic view of the circuit breaker of Figures 1 and 2 and illustrates the initial trip position.

Figure 5 is a schematic view of Figures 1 and 2 and illustrates the position of the various components when the circuit breaker is in the collapsed position, prior to the relatching of the trip latch.

Figure 6 is a schematic View of Figures 1 and 2 illustrating the position of the components when the circuit breaker is in the fully open position of Figure l with the trip latch re-engaged.

Figure 7 is a schematic view of the circuit breaker of Figures 1 and 2 and illustrates the position of the circuit breaker in the trip-free position. This figure also illustrates the latched control relay and closing solenoid which may comprise the automatic closing means for the circuit breaker. This figure further illustrates my novel means to render the instantaneous trip armature effective until after the contacts have latched closed.

Figure 8 is a view in perspective, partially broken away, of the complete long and short time delayed trip armatures and control means thereof, as well as the instantaneous trip armature.

Figure 9 is a side partial view similar to Figure 1 and illustrates a second embodiment of my invention.

The circuit breaker is provided with the trip mechanism shown in Figure 8 which has an instantaneous trip armature 122, a long time delay armature 132 controlled by dash pot 133 and a short time delay armature 142 controlled by the escapement mechanism 73. All three armatures 122, 132 and 142 are pivotally mounted on a common pin 521 and are free to operate independently.

The speed of the short time delay armature 142 of the overcurrent trip coil 139 is controlled by the timer arm 500 which is pivoted on shaft 514 of the timer mechanism. The timer arm 500 is secured to the short time delay escapment mechanism which is identified by the numeral 73 in Patent 2,769,057 and Re. 24,149, assigned to the assignee of the instant application.

The short time delay escapement mechanism for the timer arm 500 may be identical to that described in the above identified co-pending applications and forms no part of the instant invention.

The dash pot 133, which controls the long time delay armature 132 is described in Patent 2,769,057 and Re. 24,149, Serial No. 424,416, filed April 20, 1954, Serial No. 424,369, filed April 20, 1954, all assigned to the assignee of the instant application and forms no part of my present invention. For purposes of simplification, I have not shown either the long or short time delay armatures 132, 142 or their control means in Figures 1, 2 and 7.

On the occurrence of an overcurrent condition, coil 139 on the core 141 is energized. Each armature 122, 132 and 142 has a screw 124, 134, 144, respectively, threaded at one end thereof which is used to effect an adjustable contact with the initial tripping member as seen in Figures 1, 2 and 7. The head of the screw tends to act to rotate bar 140 upon the energizing of the coil 139 by hitting extension plate 146 which is bolted to the shaft 140. When the screw hits the ends of the extension plate 146, the shaft 140 is caused to rotate in a counterclockwise manner looking from the right of the circuit breaker 30, which is the view of Figure 1.

The instant invention is directed to means to place a blocking means in the path of movement of the instantaneous trip armature 122 following the manual or automatic closing of the circuit breaker and to remove the blocking means therefrom during manual, shunt or automatic tripping of the circuit breaker. Although the circuit breaker per se with which my novel arrangement may be coordinated, forms no part of the instant invention, a description of the operation of the unit will now be given in order to understand the cooperation of the circuit breaker.

It will be apparent to those skilled in the art that my invention could be applied either to the circuit breakers shown in Patent 2,754,389 and Patent 2,769,057, assigned to the assignee of the instant application, or to any other type of circuit breaker.

The circuit breaker may be tripped by shunt trip coil 150, overcurrent coil 139 or manually by handle 184. The shaft 140 is caused to rotate by means of the shunt trip coil 150 which upon being energized exerts a pull on armature member 151. The member 151 has a link 152 rigidly attached to one end of member 151 by means of an adjustable link member 154. A restoring spring 147 attached to the member 151 resets the armature upon deenergization of the coil 150. The other end of link 152 passes through tripper bar extension 156 which is attached to the shaft 140 by means of bolts passing through hole 161.

Thus, the shaft 140 can be caused to rotate by two methods: (1) due to the energization of the overcurrent trip coil 139 and (2) due to the energizing of the shunt trip coil 150. The rotation of shaft 140 causes a link 162 to be moved by means of an angle 163 which is bolted to the shaft 140. The link 162 has two slots 168 and 167. The slot 167 engages the identation of angle 163.

The translatory movement of link 162 causes the rotation of a milled shaft 170. The milled shaft 170 has another angle 171 rigidly attached to it by means of two bolts 172. This angle has an indentation 173 which engages the slot 168 of link 162.

Thus, the rotation of shaft 140 causes the rotation of milled shaft 170. When milled shaft 170 rotates to release a latch 177, as is hereinafter described,\thescir= cuit breaker movable contacts 61 are disengaged from'the stationary contacts 60.

The angle 171 described above has an abutment 178. This abutment 178' is engaged by a roller 179 which is rotated manually by means of the closing handle 1'84 attached to the shaft 180. Shaft 180 has a crank 181 rigidly attached thereto by means of a screw 182. When the'roller 179 is rotated by the closing handle 184- it engages abutment 178 of angle 171 and rotated milled shaft 170.

Thus, milled shaft 170 can be made to rotate by a plurality of methods to open the circuit breaker 30. It can be made to rotate manually by means of closing handle 184; it can be made to rotate by means of an overcurrent condition in trip coil 139 and it can be made to rotate'by means of an excitation of shunt trip coil 150, as described above.

The latch 177 is an integral part of the trip arm 185. The latch 177 engages the milled shaft 170 so that a small revolution of shaft 178 releases the latch 177. The shaft 170 is milled slightly past center at 186. The trip arm 185 is pivoted at 187 on a long pin 188. The pin 188 is also engaged on the trip arm extension 189 at point 183. The movable arm 191) is pivoted on pin 188 and extends beneath a roller 193. The roller 193 is the pivot point of a toggle mechanism consisting of two links 194 and 195 and is carried by a pin 202 which pivots the meeting of links 194 and 195 which are each comprised of two arms. Arms 19 1 are pivoted on floating pin 196 and arms 195 are ivoted on pin 28 1.

The arms 194 support a rod 197 at 198 and 199,'respectively. The rod 197 carried one end of a restoring spring 283 which is tensed by means of a stationary shaft 212. The restoring spring. 203 exerts a tension on the link 194 which tends to open or break the toggle mechanism 194195. Link 194 is pivoted on a floating pin 196, which is supported by link arm 195 and its extension-189, being parallel to the pin 188. The other link 195 of the toggle is pivoted on movable link 201) which is connected by means of an adjustable insulator 201 to the movable contact assembly 61 and pivoted on common bar 406.

When the toggle mechanism consisting of links 194 and 195 is straightened out by means hereinafter described, pressure is put on movable link 280 by means of'link 195 and bearing pin 2114. The movable link 2118 is pinned to insulator 2131 by pin 205 and moves so as to advance the insulator 201 and the movable contacts 61 towards the stationary contacts 61 In the exploded view shown in Figure 1, the contacts are open and the toggle mechanism 194-195 is collapsed.

The circuit breaker may be closed by a variety of methods such as manually by handle 184 or automatieally by latched relay 3183-241 and closing coil 321.

The circuit can be closed manually by means of shaft 188 rotated by closing handle 184, described above. If shaft 188 is rotated in the direction indicated by the arrow 18441, the roller 179 will engage the bottom of arm 190 and force the arm-198 against the roller 193 thus straightening out the toggle mechanism and closing the circuit breaker contacts.

The movable links 208 are under an opening tension by'means of opening spring 210 so that if no additional locking action other than described above for supporting the toggle existed, the circuit breaker would reopen immediately upon releasing the shaft 180. The locking device is supplied by means of a crank 211 which is located on a shaft 21., mentioned above, whose longitudinal axis is parallel to the axis of the milled shaft 170, and the rod 141 The prop 211 has two arms 213 and 214. The latch 213 is located, when the circuit breaker is open, adjacent the roller 193. When the roller 193 is forced upward, as due to the pressure of prop latch 190, the roller pushes against prop latch 213 of crank 211, rotating the crank 6. 21'1slightly'on shaftv 212.. When the roller 193:has cleared the top of prop latch 213, the prop latch 213 snaps underneath the roller 193 due to the biasing-action of spring 221). The spring 220 which is wound on the shaft 212 has one end on an indentation 221 of crank 211, the other end borne against a shaft 222 whichpierces the trip latch185. The shafts 212 and 222 have been moved out of position in the exploded view for the sake of clarity. Actually, the shaft 222 pierces the trip latch at point 287. The longitudinal axis of shaft 222 is essentially parallel to the longitudinal axis of shaft 212 and milled shaft 170.

When the roller 193 is moved, straightening the toggle 194.195, it causes crank 211 to rotate compressing spring 220. The roller 193 clears the topof prop latch 213 letting the crank rotate in the opposite direction until the arm 213 is directly beneath and supporting the roller 193. The other arm 214 or crank 211 bears against the shaft 222 preventing further rotationof the crank 211 so that the arm 213 is stopped directly beneath the rollerv 193. The spring 220 is under compression normally so that the arm 214 is constantly bearing against the shaft 222. When the toggle is straightened, the rotation of the crank 211 moves the arm 214 away from the shaft 222 until the roller 193 clears the top of prop latch 213. Then the reverserotation of the crank 211 occurs until the arm 214 bears against shaft212.

Thus, when the toggle 194195 is straightened and the circuit breaker closed, the crank 211 locks the toggle 194195 andthus locks the circuit breaker in a closed position.

The closing handle 184 by means of the shaft 180. after closing the circuit breaker by means of the rotation of roller 179 against the arm 198, as described above, is returnedto its normal position by means of a crank 230. The crank 230 is pivoted on a stationary pin 231.

The crank 181 described above has an indentation 232 which meets a roller 233 of crank 230. The crank 231) supports a pin 234 which has a restraining spring 235 engaged at one end 236. The restraining spring 235 is attached to an angle 237 and is tensed on the pin 236, causing the crank 230 to rotate. The rotation of crank 238 causes the roller 233 to meet the indentation 232 returning the crank 181 to its normal position.

The various positions of the operating mechanism are shown in Figures 3 through 6.

Figure 3 shows the closed position thereof, with link pushed forward to raise the crank 201) and close the insulator 201 and contact arm 78 and with the roller 193 on the prop latch 213;

The latch arm 185 is shown inappropriate latching engagement with the milled shaft 170.

When the shaft'180 described above, is turned to release the mechanism or on the occurence of tripping con ditions, the milled shaft 170. is rotated to permit the latch arm 185 to move into the milled section 186 of the milled shaft 170, as seenin Figure 4.

Then as seen in Figure 5, the roller 193 drops off the prop latch abutment 213 to open the circuit breaker.

Thereafter, as seen in Figure 6; the latch' arm 185 is restored to its initial position so that the circuit breaker may again be manually moved from the open position to the closed position of Figure 3 by handle 180.

The circuit breaker may also be automatically closed by means of the latched control relay having coil 360 and armature 381 and the closing solenoid 241 which controls the closing plunger 240.

The circuitry for the automatic closing means is shown in Figure 7 and the details of the latched relay and closing solenoid are seen in Figures 1 and 7. A detailed description of the operation of the closing means shownin these figures is set forth in co-pending applications Serial No. 254,349,-filed November], 1951; Serial No. 383,714, filed October 2, 1953; Serial No. 423,782, filed 'April 16, 1954; Serial No. 428,638, filed May 10,- 1'954', all of which are assigned to the assignee of the instant application.

Figure 7 also illustrates the trip-free operation of the circuit breaker. Thus, for example, when the breaker is automatically closed by means of the control relay 30b-3tl1 and the closing solenoid 240-241, the circuit breaker then will trip-free providing the above described trip latch 170 is opened as soon as fault current flows through the contacts. That is, even though a continuous closing force may be applied to the breaker from the closing plunger 240 the circuit breaker will nevertheless trip-free, if the trip latch 170 is rotated.

As' heretofore noted, the trip latch 170 may be controlled by the overcurrent short time delay armature 142 or overcurrent long time delay armature 132. However, as heretofore noted my invention provides the breaker with an instantaneous armature 122 which is operative only during the closing operation by means of handle 184 or closing means 300301 and 24tl241.

If an attempt is made to either automatically close the breaker by means of the plunger 24s or manually close the breaker by means of the handle 184- on a fault line, the magnetic forces would tend to separate the cooperating contacts 60, 61.

The opening magnetic forces on cooperating contacts 60, 61 may be greater than the closing force which is derived from the energy flowing in the closing solenoid 241 or may be greater than the force derived when manually closing by handle 184. Without my novel instantaneous armature arrangement, the circuit breaker contacts 6%, 61 will tend to separate due to the magnetic forces, but the trip latch 170-486 will remain engaged since there is a time delay on the armatures 132 and 142 which controls the position of the trip latch. It is also possible that only the arcing contacts of the circuit breaker will engage, and remain in engagement since there is an insuflicient force to close the circuit breaker, against a fault thereby damaging these contacts and the circuit breaker.

Hence, the components will attempt to assume the position in Figure 6. However, since a closing force will be continuously applied, thereby driving the plunger 24% upwardly, a second attempt will be made and the above noted operation will be repeated. Hence, there will be chattering or pumping of the cooperating contacts which will result in damage to the circuit breaker and line to be protected thereby.

Since the circuit breaker is constantly being made and broken the armature 132 and 142 of the trip coil 139 will always be moved back to their neutral position. That is, the current will not be permitted to flow for a suflicient length of time to allow the armatures to move from their energized position against the time delay created by the timer arm 5% or dash pot 133. I It is a primary object of my invention to provide a novel arrangement wherein the circuit breaker has instantaneous trip characteristics when it is being closed on a fault current and thereafter when the contacts are latched closed has either long or short time delay trip characteristics.

As heretofore noted, I have provided the circuit breaker with an instantaneous trip armature 122 which is seen in Figures 1, 2, 7 and 8. A blocking means 530 is selectively positioned in the path of movement of the instantaneous trip armature 122. Thus, for example, as seen in Figure 1, when the circuit breaker contacts 61 61 are in the open position the blocking means 530 is removed from'the path of movement of the instantaneous trip armature 122. However, the blocking means 531) is not interposed in the path of the armature 122 until after the contacts have latched closed. Thus, as clearly seen in Figure 5, wherein the circuit breaker has tripped free, the instantaneous armature 122 is effective to trip the circuit breaker without delay since the blocking means 530 did not interfere with its operation.

However, after the circuit breaker contacts are latched closed, the blocking means 530 is interposed in the path of movement of the armature 122 as clearly seen in Figure 2.

The manner in which the blocking means 539 is controlled and coordinated with the operation of the circuit breaker will now be described in connection with the Figures 1, 2 and 7. The blocking means 530 is rigidly secured to the common shaft 510 and hence rotation therewith.

A bell crank member 531 is also secured to the common shaft 510 and is provided with an extension arm to which a biasing spring 532 is secured to bias the shaft 510 in a counterclockwise direction. The other arm of the bell crank 531 is provided with a plurality of teeth 533 which are in engagement with the teeth 534 of the member 535.

The rack 535 has a considerable mass and is guided in a vertical path by its slots 536, which receive the stationary pins 537. Thus, as the heavy rack 535 is moved upwardly the ratchet 531 will be rotated in a clockwise direction due to the engagement between the teeth 533 and 534. This will cause the common shaft 510 to rotate in a clockwise direction thereby moving the blocking member 539 in a direction of the arrow 538 to a position where it will block the clockwise rotation of the instantaneous trip armature 122.

A helical spring 539 is secured at one end to the surplus weight rack 535 and at the opposite end to one end of rod 502. The opposite end of the rod is pivotally mounted on pin 5193 to the movable link 2%. Thus, when the circuit breaker contacts are in the open position of Figure l, the rod 592 will be in its lowermost position and hence, the rack 535 will also be in its lowermost position thereby rotating the ratchet 531 and the blocking means 530 to their clockwise position.

In this position the mechanical blocking means 530 is out of the path of movement of the instantaneous trip armature 122. It will be noted that both the gear train 535 and the biasing spring 532 will tend to maintain the blocking means 539 in its unblocked position of Figure l until after the contacts 60, 61 have latched closed.

Hence, if an attempted closing operation is made on a fault line the instantaneous trip armature 122 will cause a release of the trip latch 17i)185 without time delay so that the circuit breaker will trip-free, as seen in Figure 7.

It will be noted that if the cooperating contacts it), 61 are moved toward their closing position, the movable member 2% will be rotated about the common shaft 406 in a counterclockwise direction, thereby lifting the link 502 upward.

However, the gear rack 535 which has a substantial surplus weight will not be moved upwardly instantaneously due to the spring connection 539 between the link 502 and the gear train 535. Hence, the initial movement upwardly of the movable link 502, as a result of the closing operation of the circuit breaker will tend to tension the spring 539 and store energy therein, while the gear rack 535 remains stationary.

However, in the event the circuit breaker is closed on a normal line, i. e. rated current flowing therethrough, the cooperating contacts 6t 61 will be latched closed by means of the latch 170-185 and 213-193. The stored energy in the spring 539 will lift the gear rack 535 upwardly.

Since the teeth 533 of the ratchet 531 are in mesh engagement with the teeth 534 of the gear train 535, ratchet 531 will be rotated in a clockwise direction by the upward movement of the mass member 535. This will result in the clockwise rotation of the common shaft 510 thereby interposing the mechanical blocking means 530 in the path of the instantaneous armature 122. Hence, in the event an overcurrent condition should exist thereafter, the circuit breaker will be opened by either the short time delay trip armature 142 or the long time delay tri-p armature 132.

Itwill be'noted that after the contacts have latched closed-and the mechanical blocking means 530 is rotated in a clockwise direction by means of the common shaft 510 that the biasing spring 532 will be tensioned and energy thus stored therein.

However, the spring 539 dominates over the spring 532 and hence the biasing spring 532 will be ineffective to rotate the ratchet 531 in a counterclockwise direction.

If the circuit breaker is tripped open by either energization of the overcurrent coil 139 or manually by means of the handle 184 or by means of the shunt trip device 150 the movable member 200 will be moved downwardly. Hence, the link 502 will be moved downwardly due to its being pivotally mounted on the member 200.

Accordingly, the mass member 535 will no longer be supported in its upward position and hence, will tend to move down. Furthermore, the stored energy in the biasing spring 532 can now be released to thereby aid in rotating the ratchet 531 in a counterclockwise direction, which will aid in moving the rack 535 downwardly. The downward movement of the gear rack 535, due to the mesh engagement of its teeth 534 with the teeth 533 of the ratchet 531, will cause this member to rot-ate in a counterclockwise direction, thereby rotating the common shaft 510 and the blocking means in the same direction;

Hence, the blocking means for the instantaneous armature 122 will be removed when the circuit breaker is being operated to the open or trip position. Thus, the instantaneous armature 122 is again rendered operative when the circuit breaker is re-closed either manually by the handle 184 or automatically by the closing means 300-301 and 240-241, to thereby provide instantaneous trip operation in the event a fault current exists on-the line.

In the drawings of Figures 1, 2 and 7, I have shown myinvention in connection with pole of the circuit breaker. However, it will be apparent to those skilled in the art that the common shaft 510 can extend past each pole of a multi-pole circuit breaker, so that the instantaneous armature 122 associated with each pole can be rendered operative or inoperative by means of its associated blocking means 530 which will be mounted on the common shaft 510.

In Figure 9, I have shown a second embodiment of my invention which provides means to render the instantaneous armature 122 inoperative after the contacts have latched closed. In the second embodiment of Figure 9, the control and coordination of the blocking means 530 is achieved by means of a spring arrangement rather than by a rack and ratchet mesh engagement.

In this embodiment, the rod 502' is moved upwardly whenever the contacts are moved to engaging position and downwardly whenever the contacts are moved to the disengaged position.

The link 502 is pivotally connected to the link 540 which, in turn, is rotatively mounted on a common shaft 510. A member 541, having substantial mass, is rigidly secured to the common shaft 510. Spring members 542 and 543 are secured between the link 540 and the member 541.

As heretofore noted, the heavy blocking member 530 is also rigidly mounted on common shaft 510. When the circuit breaker contacts 6%), 61 are in a disengaged position and the link 502 thereby in its lowermost position, the biasing springs 542543 will tend to hold and maintain the member 541, the shaft 510, and the blocking member 530 in their extremely counterclockwise position against the stop member 544. In this position, the instantaneous trip armature 122 is rendered operative and free to trip open the circuit breaker.

When the circuit breaker contacts 60, 61 are moved toward their engaged position, the link 502 will be moved upwardly thereby rotating the link 5456 upwardly. Since the link 540 is free to rotate on the common shaft 510, this latter member will not be initially rotated. However, the upward movement of the link 540 tends to rel-ax by '1'0 spring 543 andtension the spring542 thereby storing energy therein.

If the circuit breaker is closedon a fault current theinstantaneoustrip armature 122 will be operative-to trip the circuit breaker without time delay as heretofore de' scribed. However, if the circuit breaker should be closed on a normal line then the stored energy in the biasing spring 543 will tend to rotate the member 541 and the shaft 510 and the blocking means 530 in a clockwise direction after the contacts have latched closed.-

Rotation of these-members in a clockwise direction will: thereby move the blocking means in the direction of the arrow 538 so that the instantaneous trip armature is rendered inoperative to trip the circuit breaker, in the event an-over-current or fault current shouldexist on the line. If the circuit breaker should subsequently be tripped or opened either by means of the overcurrent coil 139 or the shunttrip coil or manually by means of the handle 184 the rod will then be moved dOWl1- wardly thereby relaxing the spring 542 and storing energy in the spring 543.

Since the link 540 is rotatably mounted on the shaft 510 the blocking means 530 and member 541 will not be initally rotated thereby.

However, the stored energy in the spring 543 will subsequently cause'the rotation of member 541, shaft: 510 and blocking means 530 in a counterclockwise di-- rection to thereby remove the blocking member 530: from the path of movement of the instantaneous anna ture 122 to render the same operative in the event the" circuit breaker is closed on a fault-current.

In the foregoing, I have described my invention only in connection with preferred embodiments thereof. Many variations and modifications of the principles of' my invention within the scope of the description herein are obvious. Accordingly, I prefer to be bound not by the specific disclosure herein, but only by the appending, claims.

I claim:

1. In a circuit breaker having a pair of cooperatingv contacts with an initially engaged, a final engaged and a disengaged position, overcurrent trip means operatively connected to said circuit breaker to move said cooperating contacts from said engaged position to said disengaged position; said overcurrent trip means being comprised: of a time delay armatureand an instantaneous armature,- said instantaneous armature effective to cause trippingoperation of said circuit breaker when said circuit breaker is being closed on a fault line and said circuit breaker is in said initially engaged position, said time delay armature elfective to cause automatic tripping operation of said circuit breaker when said circuit breaker contacts are in said final engaged positionand a fault current flows through said contacts; means operatively connected and,

controlled by the movement of said interrupter to render said instantaneous armature operative to cause tripping operation of said circuit breaker without time delay when said circuit breaker is in said initially engaged position; said means comprising an energy storage device in which energy is stored while said circuit breaker is moved from said disengaged position to said initially engaged position and released when said circuit breaker is moved from said initially engaged position to said final engaged position.

2. In a circuit breaker having a pair of cooperating contacts with an initially engaged, a final engaged and a disengaged position, overcurrent trip means operatively connected to said circuit breaker to automatically move said cooperating contacts from either of said engaged positions to said disengaged position; said overcurrent trip means being comprised of a time delay armature and an instantaneous armature, a blocking means interposed in the path of movement of said instantaneous armature when said circuit breaker contacts are in said final engaged position, means operatively connected to said circuit breaker to control and coordinate the move ment of said blocking means with the operation of said circuit breaker, said means being comprised of a mass member which delays the movement of said blocking member to the path of said instantaneous armature until after said circuit breaker contacts have been moved from said initial engaged position to said final engaged position.

3. In a circuit breaker having a pair of cooperating contacts having an initially closed position, a latched closed position and an open position, a tripping means operatively connected to said circuit breaker, said trip means being comprised of an instantaneous trip member and a time delay trip member; a mechanical blocking member for said instantaneous trip member, control means operatively connected to said blocking means, said control means connected to and operated by said circuit breaker to move said blocking means out of and into the path of movement of said instantaneous trip member when said circuit breaker contacts are moved from said latched closed position to said open position and when circuit breaker contacts are moving from said open position to said latched closed position; said control means including a spring means energized when said circuit breaker is moved from said open position to said initially closed position; said blocking means being moved into the path of movement of said instantaneous trip member by said spring means when said circuit breaker is moved from said initially closed position to said latched closed position.

4. In a circuit interrupter having an initial closed position, a latched closed position and an open position, trip means operatively connected to said circuit interrupter and being comprised of a time delay member and an instantaneous member, a mechanical blocking means operatively connected with said instantaneous member, a control mechanism connected to said circuit interrupter and said blocking member, said control mechanism being comprised of a heavy mass member suspended from a spring which is controlled by the operation of said circuit interrupter, said mass member being operatively connected to said blocking means to move said blocking means into the path of movement of said instantaneous member after said circuit interrupter has been moved past said initially closed position to said latched closed position; said mass member being operatively connected to said blocking means to maintain said blocking means out of the path of movement of said instantaneous member while said circuit interrupter is being moved from said open position to said initially closed position and energy is being stored in said spring.

5. In a circuit interrupter having an initially engaged 12 position, a finally engaged, a latched position and an opened position; said circuit interrupter having an instantaneous trip means; a blocking member operatively connected with said instantaneous trip means to selectively render said instantaneous trip member operative and inoperative; a first biasing member connected and positioned to be energized by the movement of said circuit interrupter from said finally engaged position to said open position, said first biasing member connected to said blocking means to move said blocking means to said operative position; a second biasing member connected and operated by the movement of said circuit interrupter from said open position to said initially engaged position, said second biasing member connected and positioned to move said blocking member to said inoperative position when said circuit interrupter has moved from said initial engaged position to said finally engaged position.

6. A circuit interrupter having an initially closed, a latched closed and an open position; a trip means operatively connected to said circuit interrupter to automatically trip said circuit interrupter from either said latched closed position or said initially closed position to said open position; said trip means including a time delay trip member and an instantaneous trip member; a blocking means, a linkage means and a biasing m ans; said linkage means including said biasing means and being operatively connected to said blocking means; said linkage means being operatively connected to said circuit interrupter to selectively interpose said blocking means in the path of movement of said instantaneous trip member; said linkage means operative to remove said blocking means from the path of movement of said instantaneous armature when said circuit interrupter is moved from said latched closed to said open position; said biasing means storing energy when said circuit interrupter is moved from said open position to said initially closed position; said blocking means remaining removed from the path of movement of said instantaneous trip member while said circuit interrupter is in said initially closed position; said biasing means releasing its energy through a portion of said linkage means when said circuit interrupter is moved from said initially closed position to said latched closed position to thereby move said blocking means in the path of movement of said instantaneous trip member.

References Qi'ted in the file of this patent UNlTED STATES PATENTS 2,393,736 Bennett et al. Jan. 29, 1946 2,433,602 Wallace et al. Oct. 4, 1949 2,696,536 Coggeshall et al. Dec. 7, 1954 2,709,731 MacNeill May 31, 1955 

